1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_OPTO_MULTNODE_HPP
26 #define SHARE_OPTO_MULTNODE_HPP
27
28 #include "opto/node.hpp"
29
30 class Matcher;
31 class ProjNode;
32
33 //------------------------------MultiNode--------------------------------------
34 // This class defines a MultiNode, a Node which produces many values. The
35 // values are wrapped up in a tuple Type, i.e. a TypeTuple.
36 class MultiNode : public Node {
37 public:
38 MultiNode( uint required ) : Node(required) {
39 init_class_id(Class_Multi);
40 }
41 virtual int Opcode() const;
42 virtual const Type *bottom_type() const = 0;
43 virtual bool is_CFG() const { return true; }
44 virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
45 virtual bool depends_only_on_test() const { return false; }
46 virtual const RegMask &out_RegMask() const;
47 virtual Node *match(const ProjNode *proj, const Matcher *m, const RegMask* mask);
48 virtual uint ideal_reg() const { return NotAMachineReg; }
49 ProjNode* proj_out(uint which_proj) const; // Get a named projection
50 ProjNode* proj_out_or_null(uint which_proj) const;
51 ProjNode* proj_out_or_null(uint which_proj, bool is_io_use) const;
52 };
53
54 //------------------------------ProjNode---------------------------------------
55 // This class defines a Projection node. Projections project a single element
56 // out of a tuple (or Signature) type. Only MultiNodes produce TypeTuple
57 // results.
58 class ProjNode : public Node {
59 protected:
60 virtual uint hash() const;
61 virtual bool cmp( const Node &n ) const;
62 virtual uint size_of() const;
63 void check_con() const; // Called from constructor.
64 const Type* proj_type(const Type* t) const;
65
66 public:
67 ProjNode( Node *src, uint con, bool io_use = false )
68 : Node( src ), _con(con), _is_io_use(io_use)
69 {
70 init_class_id(Class_Proj);
71 // Optimistic setting. Need additional checks in Node::is_dead_loop_safe().
72 if (con != TypeFunc::Memory || src->is_Start())
73 init_flags(Flag_is_dead_loop_safe);
74 DEBUG_ONLY(check_con());
75 }
76 const uint _con; // The field in the tuple we are projecting
77 const bool _is_io_use; // Used to distinguish between the projections
78 // used on the control and io paths from a macro node
79 virtual int Opcode() const;
80 virtual bool is_CFG() const;
81 virtual bool depends_only_on_test() const { return false; }
82 virtual const Type *bottom_type() const;
83 virtual const TypePtr *adr_type() const;
84 virtual bool pinned() const;
85 virtual Node* Identity(PhaseGVN* phase);
86 virtual const Type* Value(PhaseGVN* phase) const;
87 virtual uint ideal_reg() const;
88 virtual const RegMask &out_RegMask() const;
89
90 #ifndef PRODUCT
91 virtual void dump_spec(outputStream *st) const;
92 virtual void dump_compact_spec(outputStream *st) const;
93 #endif
94
95 // Return uncommon trap call node if proj is for "proj->[region->..]call_uct"
96 // null otherwise
97 CallStaticJavaNode* is_uncommon_trap_proj(Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const;
98 // Return uncommon trap call node for "if(test)-> proj -> ...
99 // |
100 // V
101 // other_proj->[region->..]call_uct"
102 // null otherwise
103 CallStaticJavaNode* is_uncommon_trap_if_pattern(Deoptimization::DeoptReason reason = Deoptimization::Reason_none) const;
104
105 // Return other proj node when this is a If proj node
106 ProjNode* other_if_proj() const;
107 };
108
109 /* Tuples are used to avoid manual graph surgery. When a node with Proj outputs (such as a call)
110 * must be removed and its ouputs replaced by its input, or some other value, we can make its
111 * ::Ideal return a tuple of what we want for each output: the ::Identity of output Proj will
112 * take care to jump over the Tuple and directly pick up the right input of the Tuple.
113 *
114 * For instance, if a function call is proven to have no side effect and return the constant 0,
115 * we can replace it with the 6-tuple:
116 * (control input, IO input, memory input, frame ptr input, return addr input, Con:0)
117 * all the output projections will pick up the input of the now gone call, except for the result
118 * projection that is replaced by 0.
119 *
120 * Using TupleNode avoid manual graph surgery and leave that to our expert surgeon: IGVN.
121 * Since the user of a Tuple are expected to be Proj, when creating a tuple during idealization,
122 * the output Proj should be enqueued for IGVN immediately after, and the tuple should not survive
123 * after the current IGVN.
124 */
125 class TupleNode : public MultiNode {
126 const TypeTuple* _tf;
127
128 template <typename... NN>
129 static void make_helper(TupleNode* tn, uint i, Node* node, NN... nn) {
130 tn->set_req(i, node);
131 make_helper(tn, i + 1, nn...);
132 }
133
134 static void make_helper(TupleNode*, uint) {}
135
136 public:
137 TupleNode(const TypeTuple* tf) : MultiNode(tf->cnt()), _tf(tf) {}
138
139 int Opcode() const override;
140 const Type* bottom_type() const override { return _tf; }
141
142 /* Give as many `Node*` as you want in the `nn` pack:
143 * TupleNode::make(tf, input1)
144 * TupleNode::make(tf, input1, input2, input3, input4)
145 */
146 template <typename... NN>
147 static TupleNode* make(const TypeTuple* tf, NN... nn) {
148 TupleNode* tn = new TupleNode(tf);
149 make_helper(tn, 0, nn...);
150 return tn;
151 }
152 };
153
154 #endif // SHARE_OPTO_MULTNODE_HPP